用通项公式#include #include #include int main(){ double fn; //第1000个用long存不下,要用double fn = pow((1+sqrt(5))/2, 1000)/sqrt(5) - pow((1-sqrt(5))/2, 1000)/sqrt(5); //把里面的1000换成N,就可以求N项 printf("F(1000) = %lf\n", fn); return 0;}